The pavement systems containing cement-bound layers have been used worldwide for over a century, with great success. Portland cement can be used in virtually every layer in a pavement system. Typical applications include improving the quality of subgrade soils and stabilizing base materials. Integrating multiple cement-based layers into a pavement design may provide a cost-effective method for achieving a stronger, more durable, sustainable pavement. For instance, using a cement-modified soil and cement-treated base as opposed to an unbound granular base placed on an unprepared subgrade can reduce the required thickness of the base material. In addition, a cement treated base may decrease the thickness needed for the concrete or asphalt surface, resulting in less materials and overall reduced cost. In addition to being the key constituent of new concrete pavement and concrete overlay surfaces, other unique surface applications of cement include roller compacted concrete (RCC), precast pavements, and pervious concrete pavements. Cement is also use in numerous pavement repair techniques, as well as an array of pavement recycling and reclamation applications.
Mixtures for concrete pavements typically incorporate the following constituents: a blend of coarse and fine aggregates, Portland cement, water, and sometimes other cementations materials such as fly ash and slag cement, and/or chemical ad mixtures (see FIG. 1).
Although cement and concrete systems have adequate properties for many construction applications, there are many properties, like strength or deformation, which are not acceptable.
Polymer latex modified Portland cement systems develop significant changes in physical properties when compared against unmodified concrete and cement mortar. There are many patents about the use of latex-modified cement systems, specifically from styrene-butadiene polymer latex (SBR random), acrylic latex, EPDM and Ethylene vinyl acetate (EVA) latex to Portland cement having improved strength, flexibility, adhesion, elongation at break and others. However, there are not any patents describing the use of SBS latex. This type of latex is not reported in literature for concrete modification.